1. Technical Field
The present invention relates to an optical waveguide film, a method of producing the same, and an optical transmitter and receiver module.
2. Related Art
Flexible electric wiring circuits have come to be widely used in general. With demands for higher speed signal processing techniques, transmission at a frequency of more than one giga Hz is sought. With respect to signal transmission at a frequency of more than one giga Hz, optoelectronic printed circuit boards have been studied in which optical signal transmission is conducted so as to reduce noise.
In mobile equipment, for example, not only high-speed signal processing but also reduction in power consumption are greatly desired. From the viewpoint of reducing power consumption, optical signal transmission is disadvantageous and it is practically difficult to completely eliminate electric signaling. Even when optical signal transmission is introduced, cables for electric wiring have always been necessary since power supply to a light-receiving/emitting device is always necessary. Therefore, the need for cables for electric wiring will disappear only after a flexible photoelectric-combined optical waveguide film is realized; further, a flexible photoelectric-combined optical waveguide film has flexibility as an optical waveguide film and thus has significant practical advantages.
Although electric wiring is preferably formed of silver or a silver alloy in consideration of cost, silver or silver alloy are vulnerable to oxidation, sulfuration, and chlorination, and are thus inferior in durability. Although silver alloys exist that are obtained by adding various metals to silver, even such alloys deteriorate over time and, therefore, it has been necessary to provide a thick resin protective layer. In consideration of demands for increased flexibility of an optical waveguide film, it is necessary to minimize the thickness of the protective layer for the electric wiring.